Thermal interfacing assembly for a power module with in-place curing
A thermal interfacing assembly for use in a power module having at least one battery module and a cooling plate, and corresponding method of forming the thermal interfacing assembly. The thermal interfacing material is deposited over a first surface of the cooling plate such that the thermal interfacing material conforms to the shape of the first surface. The thermal interfacing material is configured to be electrically insulating and thermally conductive. A first embedded heater is positioned adjacent to the thermal interfacing material. The first embedded heater includes an electrically-conductive portion and a resistive portion. The battery module is installed adjacent to the first embedded heater such that the first embedded heater is directly in contact with a first face of the battery module. The first embedded heater is employed to at least partially induce in-place curing of the thermal interfacing material.
Latest General Motors Patents:
- On-vehicle ultra-wideband system and method
- Surround view vehicle egress assistance
- Application virtualization in an emulator using an authentication processor
- System and method estimating temperature of a direct current bus bar and direct current connector in a power inverter and providing control based upon the temperature
- Rotor electrical grounding system
This application is a continuation-in-part of U.S. patent application Ser. No. 16/259,295, filed on Jan. 28, 2019, which is hereby incorporated by reference in its entirety.
INTRODUCTIONThe present disclosure relates to a power module, a thermal interfacing assembly for use in the power module and a corresponding method of forming the thermal interfacing assembly. The use of purely electric vehicles and hybrid vehicles, such as for example, battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles and fuel cell hybrid electric vehicles, has greatly increased over the last few years. Fully and partially electric vehicles generally include a rechargeable energy storage component, such as a high voltage battery. The performance and life-span of the rechargeable batteries may be improved by regulating its temperature and controlling exposure to excessively high and excessively low temperatures.
SUMMARYDisclosed herein is a power module, a thermal interfacing assembly for use in the power module and a corresponding method of forming the thermal interfacing assembly. The power module includes at least one battery module and a cooling plate. The thermal interfacing material is deposited over a first surface of the cooling plate such that the thermal interfacing material conforms to the shape of the first surface. The thermal interfacing material is configured to be electrically insulating and thermally conductive. A first embedded heater is positioned adjacent to the thermal interfacing material. The first embedded heater includes an electrically-conductive portion and a resistive portion, the resistive portion being configured to have a resistance that varies with at least one of a temperature and an electric current. The battery module is installed adjacent to the first embedded heater such that the first embedded heater is directly in contact with a first face of the battery module. The first embedded heater is employed to at least partially induce in-place curing of the thermal interfacing material.
Prior to placing the first embedded heater adjacent to the thermal interfacing material, the electrically-conductive portion and the resistive portion of the first embedded heater are sandwiched between a base layer and a cover layer. The base layer and the cover layer may be at least partially composed of a respective polymer material. In one example, the resistive portion includes a positive temperature coefficient (PTC) material. The electrically-conductive portion may be patterned into a first electrode and a second electrode such that the resistive portion is in electrical contact with the first electrode and the second electrode, the second electrode being spaced apart from the first electrode on the base layer. The in-place curing may be controlled through an electric current to the first electrode and the second electrode. The base layer of the first embedded heater may be configured to have a greater thermal conductivity than the cover layer.
In one example, prior to installation of the battery module, an external jumpstarting process is employed to at least partially cure the thermal interfacing material at a jumpstart temperature. The in-place curing of the thermal interfacing material may be continued at an in-place temperature with the first embedded heater after the battery module is installed, the in-place temperature being lower than the jumpstart temperature. The external jumpstarting process may include directing a source of light towards the thermal interfacing material for a predetermined duration. Other methods available to those skilled in the art may be employed. In one example, the jumpstart temperature is 100 degrees Celsius and the in-place temperature is 50 degrees Celsius.
The thermal interfacing material may be positioned to be in direct contact with the cooling plate such that there is a zero-gap interface between the thermal interfacing material and the first surface of the cooling plate. Alternatively, prior to depositing the thermal interfacing material on the first surface of the cooling plate, a second embedded heater may be placed directly over the first surface of the cooling plate such that the second embedded heater is sandwiched between the thermal interfacing material and the first surface of the cooling plate (after the thermal interfacing material is deposited). The second embedded heater may be employed to accelerate the in-place curing of the thermal interfacing material.
The thermal interfacing material may include a plurality of thermally conductive particles interspersed in a polymeric base. The polymeric base includes at least one of or a combination of polysiloxane, polyurethane and polyacrylate. The plurality of thermally conductive particles includes at least one of or a combination of boron nitride, aluminum oxide, silicon carbide, silicon nitride, expanded graphene, aluminum nitride and zinc oxide.
The above features and advantages and other features and advantages of the present disclosure are readily apparent from the following detailed description of the best modes for carrying out the disclosure when taken in connection with the accompanying drawings.
Referring to the drawings, wherein like reference numbers refer to like components,
The cooling plate 16 and the thermal interfacing assembly 10 are configured to regulate the temperature of the battery cells 18 of the battery module 14. Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
The first embedded heater 40 is capable of controlling the temperature itself, in other words, self-regulate, by regulating its heating power through its variable electrical resistance in response to changing temperatures. At lower temperatures, the resistance of the positive temperature coefficient (PTC) material is lower, and thus its heating power is greater, resulting in a relatively rapid increase in its temperature. When the temperature increases, the resistance of the positive temperature coefficient (PTC) material increases as well and therefore simultaneously decreases its heating power. During a short period and specific temperature, the heating power decreases to a point where it balances the energy loss of the system and maintains a constant equilibrium.
The first embedded heater 40 is configured to generate and supply a regulated amount of heat to the cells 18 of the battery module 14 and the thermal interfacing material 30, via thermal conduction. Referring to
The first embedded heater 40 is employed to at least partially induce in-place curing of the thermal interfacing material 30, via thermal conduction. Curing produces the toughening or hardening of a material, resulting in an increase in viscosity or hardness. For example, a polymer may be cured by cross-linking of polymer chains. Curing the thermal interfacing material 30 in-place is challenging as the heating may not be efficiently or uniformly applied and cycle time for curing at room temperature reduces throughput. The method 100 (described below with reference to
Referring to
Alternatively, the thermal interfacing assembly 10 may include a single heater, i.e., one of the first embedded heater 40 and the second embedded heater 70. An alternative embodiment (without the second embedded heater 70) is shown in
Referring now to
Per block 130 of
Alternatively, as indicated by line 125, the method 100 may proceed from block 120 directly to block 140. Per block 140, the method 100 includes installing the first embedded heater 40 and the battery module 14. The battery module 14 is positioned adjacent to the first embedded heater 40 such that the first embedded heater 40 is directly in contact with the first face 60 of the battery module 14.
Per block 150, the first embedded heater 40 and/or second embedded heater 70 are employed to at least partially induce in-place curing of the thermal interfacing material 30. The thermal interfacing material 30 is cured or cross-linked to substantially decrease its flowability. The in-place curing of the thermal interfacing material 30 may be carried out at an in-place temperature with the first embedded heater 40 and/or the second embedded heater 70 after the battery module 14 is installed. In one example, the jumpstart temperature is 100 degrees Celsius and the in-place temperature is 50 degrees Celsius.
The controller C may be an integral portion of, or a separate module operatively connected to, other controllers of the power module 12. The controller C includes a computer-readable medium (also referred to as a processor-readable medium), including a non-transitory (e.g., tangible) medium that participates in providing data (e.g., instructions) that may be read by a computer (e.g., by a processor of a computer). Such a medium may take many forms, including, but not limited to, non-volatile media and volatile media. Non-volatile media may include, for example, optical or magnetic disks and other persistent memory. Volatile media may include, for example, dynamic random-access memory (DRAM), which may constitute a main memory. Such instructions may be transmitted by one or more transmission media, including coaxial cables, copper wire and fiber optics, including the wires that comprise a system bus coupled to a processor of a computer. Some forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, other magnetic media, a CD-ROM, DVD, other optical media, punch cards, paper tape, other physical media with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, other memory chips or cartridges, or other media from which a computer can read.
Look-up tables, databases, data repositories or other data stores described herein may include various kinds of mechanisms for storing, accessing, and retrieving various kinds of data, including a hierarchical database, a set of files in a file system, an application database in a proprietary format, a relational database management system (RDBMS), etc. Each such data store may be included within a computing device employing a computer operating system such as one of those mentioned above, and may be accessed via a network in one or more of a variety of manners. A file system may be accessible from a computer operating system, and may include files stored in various formats. An RDBMS may employ the Structured Query Language (SQL) in addition to a language for creating, storing, editing, and executing stored procedures, such as the PL/SQL language mentioned above.
As used in this specification and claims, the terms “for example,” “e.g.,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items.
The detailed description and the drawings or FIGS. are supportive and descriptive of the disclosure, but the scope of the disclosure is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. Furthermore, the embodiments shown in the drawings or the characteristics of various embodiments mentioned in the present description are not necessarily to be understood as embodiments independent of each other. Rather, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings. Accordingly, such other embodiments fall within the framework of the scope of the appended claims.
Claims
1. A method of forming a thermal interfacing assembly in a power module having at least one battery module and a cooling plate, the method comprising:
- depositing a thermal interfacing material over a first surface of the cooling plate such that the thermal interfacing material conforms to a shape of the first surface, wherein the thermal interfacing material is electrically insulating and thermally conductive;
- forming a first embedded heater with an electrically-conductive portion and a resistive portion;
- fitting the electrically-conductive portion and the resistive portion of the first embedded heater between a base layer and a cover layer, the base layer and the cover layer being at least partially composed of a respective polymer material;
- composing the resistive portion with a positive temperature coefficient (PTC) material;
- placing the first embedded heater adjacent to the thermal interfacing material, the resistive portion being configured to have a resistance that varies with at least one of a temperature and an electric current;
- installing the at least one battery module adjacent to the first embedded heater such that the first embedded heater is directly in contact with a first face of the battery module; and
- employing the first embedded heater to at least partially induce in-place curing of the thermal interfacing material.
2. The method of claim 1, further comprising:
- patterning the electrically-conductive portion into a first electrode and a second electrode such that the resistive portion is in contact with the first electrode and the second electrode, the second electrode being spaced apart from the first electrode on the base layer; and
- controlling the in-place curing of the thermal interfacing material through control of the electric current to the first electrode and the second electrode.
3. The method of claim 1, further comprising:
- employing an external jumpstarting process to at least partially cure the thermal interfacing material at a jumpstart temperature prior to installing the battery module; and
- continuing the in-place curing of the thermal interfacing material at an in-place temperature with the first embedded heater after the battery module is installed, the in-place temperature being lower than the jumpstart temperature.
4. The method of claim 3, wherein the external jumpstarting process includes:
- directing a source of light towards the thermal interfacing material for a predetermined duration.
5. The method of claim 3, further comprising:
- selecting the jumpstart temperature to be 100 degrees Celsius and the in-place temperature to be 50 degrees Celsius.
6. The method of claim 1, further comprising:
- positioning the thermal interfacing material to be in direct contact with the cooling plate such that there is a zero-gap interface between the thermal interfacing material and the first surface of the cooling plate.
7. The method of claim 1, further comprising, prior to depositing the thermal interfacing material on the first surface of the cooling plate:
- placing a second embedded heater directly over the first surface of the cooling plate such that the second embedded heater is sandwiched between the thermal interfacing material and the first surface of the cooling plate after the thermal interfacing material is deposited; and
- employing the second embedded heater to accelerate the in-place curing of the thermal interfacing material.
8. A thermal interfacing assembly for use in a power module having at least one battery module and a cooling plate, the thermal interfacing assembly comprising:
- a thermal interfacing material deposited over a first surface of the cooling plate such that the thermal interfacing material conforms to a shape of the first surface, wherein the thermal interfacing material is electrically insulating and thermally conductive;
- a first embedded heater positioned adjacent to the thermal interfacing material and the at least one battery module such that the first embedded heater is directly in contact with a first face of the at least one battery module;
- wherein the first embedded heater includes an electrically-conductive portion and a resistive portion, the resistive portion being configured to have a resistance that varies with at least one of a temperature and an electric current;
- wherein the first embedded heater includes a base layer and a cover layer sandwiching both the electrically-conductive portion and the resistive portion, the base layer being at least partially composed of a polymer material and the cover layer including a dielectric coating;
- wherein the resistive portion includes a positive temperature coefficient (PTC) material; and
- wherein the first embedded heater is configured to induce in-place curing of the thermal interfacing material.
9. The thermal interfacing assembly of claim 8, wherein:
- the base layer of the first embedded heater is configured to have a greater thermal conductivity than the cover layer.
10. The thermal interfacing assembly of claim 8, wherein:
- the electrically-conductive portion is patterned into a first electrode and a second electrode, the second electrode being spaced apart from the first electrode on the base layer;
- the resistive portion is configured to be in contact with the first electrode and the second electrode of the electrically-conductive portion; and
- the in-place curing of the thermal interfacing material is controlled via the electric current to the first electrode and the second electrode.
11. The thermal interfacing assembly of claim 8, wherein:
- the thermal interfacing material is at least partially cured with an external jumpstarting process at a jumpstart temperature prior to installation of the battery module; and
- the in-place curing of the thermal interfacing material is continued at an in-place temperature with the first embedded heater after the battery module is installed, the in-place temperature being lower than the jumpstart temperature.
12. The thermal interfacing assembly of claim 11, wherein:
- the jumpstart temperature is 100 degrees Celsius and the in-place temperature is 50 degrees Celsius.
13. The thermal interfacing assembly of claim 8, wherein:
- the thermal interfacing material is positioned to be in direct contact with the cooling plate such that there is a zero-gap interface between the thermal interfacing material and the first surface of the cooling plate.
14. The thermal interfacing assembly of claim 8, further comprising:
- a second embedded heater positioned directly over the first surface of the cooling plate such that the second embedded heater is sandwiched between the thermal interfacing material and the first surface of the cooling plate after the thermal interfacing material is deposited; and
- wherein the second embedded heater is employed to accelerate the in-place curing of the thermal interfacing material.
15. The thermal interfacing assembly of claim 8, wherein:
- the thermal interfacing material includes a plurality of thermally conductive particles interspersed in a polymeric base;
- the polymeric base includes at least one of or a combination of polysiloxane, polyurethane and polyacrylate; and
- the plurality of thermally conductive particles includes at least one of boron nitride, aluminum oxide, silicon carbide, silicon nitride, expanded graphene, aluminum nitride and zinc oxide.
16. A power module comprising:
- at least one battery module;
- a cooling plate operatively connected to the at least one battery module;
- a thermal interfacing assembly configured to interface between at least one battery module and the cooling plate, the thermal interfacing assembly having a thermal interfacing material and a first embedded heater;
- wherein the thermal interfacing material is deposited over a first surface of the cooling plate such that the thermal interfacing material conforms to a shape of the first surface, the thermal interfacing material being configured to be electrically insulating and thermally conductive;
- wherein the first embedded heater is positioned adjacent to the thermal interfacing material and the at least one battery module such that the first embedded heater is directly in contact with a first face of the at least one battery module;
- wherein the first embedded heater includes an electrically-conductive portion and a resistive portion, the resistive portion being configured to have a resistance that varies with at least one of a temperature and an electric current;
- wherein the first embedded heater includes a base layer and a cover layer sandwiching both the electrically-conductive portion and the resistive portion, the base layer being at least partially composed of a polymer material and the cover layer including a dielectric coating;
- wherein the resistive portion includes a positive temperature coefficient (PTC) material; and
- wherein the first embedded heater is configured to induce in-place curing of the thermal interfacing material.
17. The power module of claim 16, further comprising:
- a second embedded heater positioned directly over the first surface of the cooling plate such that the second embedded heater is sandwiched between the thermal interfacing material and the first surface of the cooling plate after the thermal interfacing material is deposited; and
- wherein the second embedded heater is employed to accelerate the in-place curing of the thermal interfacing material.
20150357687 | December 10, 2015 | Heeg |
20190140233 | May 9, 2019 | Yeh |
Type: Grant
Filed: Jun 3, 2019
Date of Patent: Dec 21, 2021
Patent Publication Number: 20200243927
Assignee: GM Global Technology Operations LLC (Detroit, MI)
Inventors: Evan J. Dawley (Bloomfield Hills, MI), Mahmoud Abd Elhamid (Troy, MI)
Primary Examiner: Osei K Amponsah
Application Number: 16/429,802
International Classification: H01M 10/653 (20140101); H01M 10/6551 (20140101); H01M 10/613 (20140101); H01M 10/617 (20140101); H01M 10/625 (20140101);